Question
I have trouble understanding the REFIN(+) and REFIN(-) pins on the ADuC824.
Also, whats their relation to differantial/unipolar input?
Are there any referance board like for the ADuC812, where the schematic is
available?
Answer
The reference to the ADuC824 is a true differential input. The differential
input of the reference has no relation to the ADC inputs being unipolar or
bipolar.
The reference supplied to the ADC is simply REF(+) - REF(-). The analog inputs
are always differential. The analog input range in bipolar mode is +/- {REF(+)
- REF(-)} / GAIN. In unipolar mode the input range is 0 to {REF(+) -
REF(-)}/GAIN.
You can now download the evaluation board documentation from our website:
http://www.analog.com/microconverter.